PLANET MH-1000 - Manual (Page 17)

Multi-Homing Security Gateway User’s Manual
port by replying the selected WAN IP address through the built-in DNS server. The remote PC then
accesses the network via the specified WAN port. How MH-1000 directs this traffic through the built-in DNS
server depends on whether it is configured for Fail Over or Load Balancing.
Learn how to make DNS Inbound on MH-1000 work for you in the following section.
2.5.1 DNS Inbound Fail Over
MH-1000 can be configured to reply the WAN2 IP address for the DNS domain name request should
WAN1 fail.
Built-in DNS
S
192.168.2.2
192.168.2.3
FTP
HTTP
200.200.200.1
www.mydomain.com
200.200.200.1
Authoritative Domain Name Server
f d i
Before Fail Over
100.100.100.1
After Fail Over
100.100.100.1
DNS
DNS
Built-in DNS
S
192.168.2.2
192.168.2.3
1st connection
2 nd connection
1st connection
2 nd connection
www.mydomain.com
DNS
DNS
HTTP
FTP
In the above example, an FTP Server (IP_192.168.2.2) and an HTTP Server (IP_192.168.2.3) are
connected to the Internet via WAN1 (IP_200.200.200.1) on MH-1000. A remote computer is trying to
access these servers via the Internet, and makes a DNS request. The DNS request ( www.mydomain.com )
will be sent through WAN1 (200.200.200.1) to the built-in DNS server. The DNS server will reply
200.200.200.1 because this is the only active WAN port. Should WAN1 fail, MH-1000 will instead reply with
WAN2’s IP address (100.100.100.1), and the remote PC will gain access to the network via WAN2. By
configuring MH-1000 for DNS Inbound Fail Over, incoming requests will enjoy increased reliability when
accessing your network.
Please refer to appendix D for example settings.
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